Identifying the most effective climate parameters on crop yield in rain-fed agriculture and irrigated farming in Iran

Abstract

Agriculture is an industry that has been traditionally used in Iran to meet people's daily nutritional needs. Since crops are affected by climate change, finding the best location to grow crops will improve crop yields. The Geographical Detector Model (GDM) was adopted in this study to measure the effects of four climate parameters, i.e., precipitation, temperature, humidity, and evaporation, in different seasons of the year on the yields of barley, beans, lentils, chickpeas, rapeseed, and wheat across Iran. According to the results showed, the highest crop yields across Iran come from wheat and barley. Furthermore, the yields of most crops are reduced in rain-fed agriculture, as the yield of wheat in rain-fed agriculture decreases by nearly 70% as opposed to irrigated farming. According to the findings, EA, ESU and EW with 24, 22 and 19 percent has more affected to barley. Rising temperatures to more than 26.1 °C can cause a sharp decrease in crop yields, with some crops yielding less than 0.5 tons/ha. The results also showed that wheat thrives more effectively in regions characterized by cold and extremely cold winters, where temperatures ranging from −3.5 to 0.98 yield an average of 3.88 tons per hectare in irrigated agriculture, while rainfed farming shows a recorded figure between 3.6 and 4.7 at 1.08. Provincial assessments indicate that temperature and precipitation are the key factors influencing crop productivity in regions characterized by cooler temperatures and higher rainfall. Specifically, the peak barley yield in irrigated areas was observed with spring rainfall exceeding 153 mm. Conversely, in tropical provinces with limited rainfall, humidity and evaporation emerge as the primary determinants of crop yields. In these regions, the highest barley yields were noted where evaporation levels surpassed 227 mm. Moreover, provinces located on the slopes of the Alborz and Zagros mountains are the best locations for wheat and chickpea cultivation, and the southeastern regions of Iran are not suitable for barley and lentils. The findings of this research have significant implications for water resource management, facilitating the identification of cultivation patterns across diverse climatic conditions and enhancing strategies for crop yield optimization.